1. Technical Field
The present invention relates to a circuit board and a method of manufacturing the same, and more particularly, to a circuit board capable of increasing adhesion between a circuit pattern and a via and reducing manufacturing cost and a method of manufacturing the same.
2. Description of the Related Art
As electronic products have been recently slim and high functional, circuit boards such as a printed circuit board (PCB) applied to the electronic products have been also thin and multilayer boards. To meet this trend, it is indispensable to implement a fine-pitch and thin-film circuit structure consisting of a circuit pattern of a circuit board and a via for an interlayer conduction.
A general PCB is manufactured by sequentially performing operations of preparing a core board such as a copper clad laminate (CCL), forming a via hole in the core board, forming a plating film in an inner wall of the via hole, filling the via hole with a predetermined filler, manufacturing a plug, and forming the circuit structure on the core board.
However, the circuit board manufactured through the above operations has a structure having low adhesion between a metal film formed in the inner wall of the via hole and the circuit pattern connected to the via on the core board. More specifically, a thickness of the plug of the above-manufactured circuit board is the same as or greater than a thickness of the core board. In this case, a bonding area between the circuit pattern formed on a surface of the core board and the metal film is small, which reduces the adhesion between the metal film and the circuit pattern.
Further, the above-described circuit board has a very complicated manufacturing process. For example, the process of manufacturing the circuit board includes a plug filling operation and then sequentially a buff polishing operation and an insulation layer stacking operation on the core board in which the plug is filled. As described above, in a case where the plug filling operation and the insulation layer stacking operation are separately performed, additional operations are performed between the two operations, which makes a board manufacturing process complicated and accordingly, manufacturing cost of the circuit board increases.